Red, irritated eyes, for example, are rarely caused by high levels of chlorine and generally are the result of chloramines, a byproduct of chlorine breaking down urine, fecal matter and other contaminants, says the Centers for Disease Control and Prevention. And, a 2017 study by the University of Alberta that focused on acesulfame potassium (ACE), an artificial sweetener that the human body cannot break down and is detectable when urine is in water, found that “the concentration of ACE in pools was 570 times greater than in tap water, and they estimated pools contained anywhere between 7.92 and 20 gallons of urine,” according to Real Simple.

Ick! The good news is that cdc.gov offers sound advice on maintaining a healthy, yet recreational, summer:

— Keep diarrhea sufferers out of the pool.— Take children to restrooms every hour.— Check swim diapers often and change them in restrooms, not poolside.— Shower before and after swimming.— Wash hands after swimming and before eating.— Teach young children not to pee or poop in a pool.— Do the smell test — pools should not have a strong chlorine smell or any other chemical odor.— Make sure the pool water is crystal-clear. — Ask to see an inspection report. — Bring your own test strips, available at discount, hardware and specialty pool retailers, to determine chemical levels (how to interpret information on pH level and parts per million should be indicated on the back of test strip packaging).

Swallowing pool water is to be avoided at all costs. It is difficult, especially for young children and children at play, to be cognizant of keeping mouths closed, but just that simple act can protect them from many pool-related health issues. Germs can survive in even well-maintained pools for several days.

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